1. Field of Invention
The present invention relates to a single-wire transmission interface and a method of transmission through single-wire; particularly, to a single-wire transmission interface for transmitting address and data, and a corresponding method.
2. Description of Related Art
Current communication interfaces, such as I2C, SPI, and SMBUS, require at least two transmission wires: one for transmitting data and one for transmitting clock. If transmission of data and clock can be achieved by one single-wire, it will reduce the number of pins of an integrated circuit, which is a great advantage and even greater to an integrated circuit with lower pin number. To this end, U.S. Pat. Nos. 7,127,631 and 7,080,266 disclose a method for single-wire serial transmission. As shown in FIG. 1, this method indicates three states by: long term high, long term low, and alternating high/low, of an EN/SET signal transmitted through a single-wire. When a receiver side detects a rising edge of the EN/SET signal, it is enabled to start receiving data (as shown by the waveform Enable) and generates a clock (as shown by the waveform Clock) corresponding to the EN/SET signal; simultaneously, a counter at the receiver side starts counting the number of the rising edges of the EN/SET signal (1˜n). When the receiver side detects a falling edge of the EN/SET signal, it starts counting a time-out period. If the receiver side does not detect a next rising edge within the time-out period, it will shut down the signal Enable, reset the counter, and the clock will stop accordingly.
In the foregoing prior art, it is unclear as to how it transmits the data “0”, and each data transmission period does not have a fixed time length. The time period of the enable signal from ON to OFF varies, depending on the content of the data; this is not preferred in certain applications.
In view of the foregoing, the present invention provides a single-wire transmission interface capable of transmitting address and data in a fixed time period, and a corresponding method.